The internal combustion engine is one of the corner stone inventions that have revolutionised the power generation industry, which included, inter alia, the automotive industry, the mechanical power industry, etc. Ever since its invention and further development throughout the years, there have been many inventions proposed to monitor the performance and to diagnose the problems of such engines as part of the engine maintenance process. Among various engine problems, one major cause is misfiring of the cylinders due to fuel line fault, timing belt malfunction (for gasoline engine), valve or piston ring leakage. Other engine performance issues involve mechanical malfunction due to tear and wear of various parts and loose linkages. Each problem will result in a characteristic signature in the engine vibration spectra in measurement location, peak frequency, shape and relative intensities along different directions. Therefore, in principle, a periodic routine monitoring of the engine vibration will provide information on the engine status. There have been many previous reports and patents on the use of accelerometer to diagnose internal combustion engine performance. All these prior arts apply complex systems and/or multiple sensors to try and monitor and/or diagnose this problem. Some of these prior art solutions even require the vehicle to be in a mobile state. Others need to have invasive probing of the internal combustion engine system. Thus, the methods disclosed in the prior arts require the diagnoses of an internal combustion engine to be conducted by a skilled professional and/or to be conducted in a specially equipped facility.
There is a need for a simple and non-invasive diagnosis of internal combustion engines.
Citation or identification of any reference in this section or any other section of this application shall not be construed as an admission that such reference is available as prior art for the present application.